1. Field of the Invention
The present invention relates generally to laser optics and technology making use of the isolator, and more particularly to, a polarization-dependent type directional isolator and a ring-type resonator laser making use of it.
2. Description of the Prior Art
Currently, in order to select the travelling direction of polarized light, a method for forcing only a specific polarized light to travel along one direction by use of an optical isolator has been widely used. This method has an advantage that it can prevent influence due to interference caused by a backwardly travelling light because it allows only a straight polarized light to travel along a single direction in a ring-type resonator laser. However, the conventional method has a disadvantage that it cannot obtain light travelling in the opposite direction, since it only allows the light to travel along a single direction.